This 8-bit I/O expander for the two-line bidirectional bus (I2C) is designed to provide general-purpose remote I/O expansion for most microcontroller families via the I2C interface [serial clock (SCL) and serial data (SDA)]. The major benefit of this device is its wide VCC range. It can operate from 1.65-V to 5.5-V on the P-port side and on the SDA/SCL side. This allows the TCA6408 to interface with next-generation microprocessors and microcontrollers on the SDA/SCL side, where supply levels are dropping down to conserve power. In contrast to the dropping power supplies of microprocessors and microcontrollers, some PCB components such as LEDs remain at a 5-V power supply.